package com.lesson11.waiguan;

/**
 * @author 朝花不迟暮
 * @version 1.0
 * @date 2020/9/2 19:27
 */
public class Screen
{
    private Screen(){}

    private static Screen instance = new Screen();

    public static Screen getInstance(){
        return instance;
    }

    public void up(){
        System.out.println("屏幕up");
    }

    public void down(){
        System.out.println("屏幕down");
    }
}
